Judgement has been reserved in the High Court case of a patient who fears doctors may deny him life-prolonging treatment.
Les Burke fears he will starve to death unable to communicate
Leslie Burke, who has a degenerative brain condition, fears guidance could allow food to be withdrawn against his wishes when he can no longer speak.
But the General Medical Council said his fears were unfounded.
After three days of legal argument Mr Justice Munby, said he would make his ruling "in due course".
Mr Burke, 44, from Lancaster, who has cerebellar ataxia, believes the GMC guidance is incompatible with the European Convention on Human Rights, which enshrines the right to life.
The guidance covers situations where death is not imminent, but doctors believe a patient's condition is so severe, and their prognosis so poor, that artificial nutrition or hydration - giving water - causes more suffering than benefit.
It says that if patients are no longer able to communicate their views, doctors must judge what the patient would want, based on earlier discussions or written statements, and in consultation with patient's relatives.
Dinah Rose QC, acting for the GMC, told the court on the second day of the hearing: "There is no evidence at all before the court that any doctor has ever proposed, or has any intention of proposing, that should he require artificial feeding and
hydration it would not be provided to him.
"There is no suggestion by any doctor that they believe the guidance issued by the GMC might encourage or permit them to withdraw artificial nutrition or
hydration from Mr Burke."
However she said the GMC would welcome guidance from the court if it felt there were ways their advice could be clarified.
Earlier, Richard Gordon, QC for Mr Burke, told the court: "Guidance is, or must be, we suggest, understood easily by those required to read it."
Before the hearing Mr Burke, who has needed to use a wheelchair for the last 12 years, said: "I am doing this because I may well end up in the position where I
need artificial hydration and nutrition.
"Physically my body will deteriorate, but I will be mentally alert the whole time.
"I may not be able to communicate with the doctors, and it takes two to three weeks to die when hydration and nutrition is withdrawn, and I will be acutely aware of that every single day and physically not able to do anything about
He said he would ultimately like the GMC guidelines to be withdrawn, but hoped the council would at least reconsider its recommendations.